80 Honoratus of Tucca said: "Since Christ is the truth, we ought to follow the truth rather than custom; that we may sanctify by the baptism of the Church the heretics who come to us, simply because they could receive nothing outside."
81. This man, too, is a witness to the custom, in which he gives us the greatest assistance, whatever else he may appear to say against us. But this is not the reason why heretics come over to us, because they have received nothing outside, but that what they did receive may begin to be of use to them: for this it could not be outside in any wise.
Source: On Baptism, Against the Donatists (New Advent)